Ever wonder why your floors are cold in January even after you insulated the attic? The culprit is often the rim joist โ that band of framing sitting right at your foundation line โ and most homes in Jonesboro and Trumann leave it completely bare.
The rim joist is where your floor system meets the foundation wall. It's exposed to outside air on one side and your conditioned living space on the other. A typical uninsulated rim joist in a 1,500 SF ranch home can account for 10โ15% of total envelope heat loss. That's real money leaving through a 1ยฝ-inch board.
The fix is straightforward. Most insulation contractors cut and press 2-inch closed-cell spray foam boards โ or better yet, spray 2 inches of closed-cell foam directly โ into each rim joist bay. Two inches of closed-cell hits R-13, seals air infiltration simultaneously, and meets IRC R402.1.2 requirements for Climate Zone 3 (that's us here in Northeast Arkansas). Sprayed-in-place runs roughly $1.50โ$2.25 per board foot installed, and a full rim joist treatment on an average crawl-space home usually runs $400โ$900 total.
Here in NE Arkansas, September is the perfect time to schedule this work. Crawl spaces are tolerable before winter sets in, foam cures predictably in moderate temps, and you'll feel the difference by the time December hits. Pair the rim joist with a vapor barrier in the crawl and you've knocked out two of the biggest comfort killers in one visit.
Reply to this post or DM us for a free rim joist assessment โ we serve Jonesboro, Trumann, Paragould, and the surrounding area.